Tool set for powder compacting press

ABSTRACT

A TOOL SET COMPRISING A DIE PLATE HAVING PUNCH APERTURES AND DISCHARGE APERTURES, PUNCHES FOR SAID PUNCH APERTURES CONTAINING CORE RODS HELD IMMOVABLE IN RELATION TO SAID PUNCHES AND LOCKABLE IN POSITION SO AS TO BE FLUSH WITH THE SURFACE OF SAID DIE PLATE.

Feb. 9, 1971 J. E. SMITH T L TOOL SET FOR POWDER COMPACTING PRESS Filed Oct. 15. 1968 5 Sheets-Sheet l f I 5-9 56 I, -l|l 26 r} 0 l'" B/j/ 34 i I FIGI I I II] In 2 7///// FIGZ 'lNVENTORS BY M @44 %r,

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EJECTW/G Pos/r/o/V INVENTORS Y 42 JOSEPH E. SMITH GEORGES D- D TROYER 66 62 BY 2%.4 M W ATTORNEYS Feb. 9., 1971 sMlTH ET AL I 3,561,056

' TOOL SET FOR POWDER COMPACTING PRESS Filed Oct. 15, 1968 5 Sheets-Sheet 5 m JOSEPH E. SMITH seems a 0'6 TROYER B /K M, 5M, m/, FMM

ATTORNEYS Feb. 9, 1971 W ETAL .LTOQL SET FOR POWDER COMPACTING PRESS Filed 001; g5. $1968 FIG- l2 M I BEE lawns NEW " lam NVENTOIQS JOSEPH E. SMITH GEORGES D- De TPOYER BYA/M' flea! {/27 I ATTORNFYS W Y m w 4 w m w I, Y Ma H i l 1 2E \.\/\N1Vw m a I. l h

United States Patent Ofifice 3,561,056 TOOL SET FOR POWDER 'COMPACTING PRESS Joseph E. Smith, Birmingham, and Georges D. De Troyer, Detroit, Mich., assignors to Wolverine-Pentronix, Inc., a corporation of Michigan Filed Oct. 15, 1968, Ser. N0. 767,648 Int. Cl. B30b 11/02 U.S. Cl. 1816.7 8 Claims ABSTRACT OF THE DISCLOSURE A tool set comprising a die plate having punch apertures and discharge apertures, punches for said punch apertures containing core rods held immovable in relation to said punches and lockable in position so as to be flush with the surface of said die plate.

REFERENCE TO RELATED APPLICATIONS The present invention is in substance related to US. applications Serial No. 450,427, filed Apr. 23, 1965 (now abandoned); Ser. No. 529,733 and 529,734 filed Feb. 24, 1966 (now US. Patents Nos. 3,328,840 and 3,344,213 respectively); Serial No. 529,842 filed Feb. 24, 1966 (now US. Patent No. 3,328,842); Ser. No. 544,285 filed Apr. 21, 1966 (new US. Patent No. 3,414,940); and Ser. No. 618,230 filed Feb. 23, 1967 (now US. Patent No. 3,415,142).

BACKGROUND OF THE INVENTION The present invention relates to powder compacting presses and more particularly to an improved tool capsule or tool set assembly for such presses having means providing an accurate adjustment of the die cavity dimensions to insure a more precise dimensional control over the finished compacted article, and further provides novel means to adjust and secure a core rod associated with said tool set assembly.

The present invention is an improvement over a tool capsule or tool set of the character provided as part of the powder compacting press disclosed in US. Patent No. 3,328,842 and copending application Ser. No. 544,- 285 filed Apr. 21, 1966, now US. Patent No. 3,414,940. The power compacting press and tool set described and claimed in the copending patent application consists of a machine for the purpose of manufacturing cores, beads,

pellets and the like, made of powdered ferrite, glass or other comparable powdered substances capable of forming a product upon the application of a pressure in a confined die cavity. The primary purpose of the machine is the manufacture of computer memory cores which are normally toroidal, pills such as pharmaceuticals, balls for ball point pens, porous bearings and bushings, and the like. Computer memory cores and porous bearings and bushings normally have a toroidal or cylindrical shape, while pharmaceuticals may take the form of tablets such as aspirin tablets, and balls for ball point pens are formed with a spherical shape.

Small compacted articles often require a high degree of dimensional control. For instance ferrite memory cores have dimensions ranging from approximately .005 to .050 inch in thickness, and from approximately .005 to .080 inch in diameter, and the tolerance of these dimensions normally must be held within *.001 inch, and

sometimes even within i.0001 inch. In addition to dimensional control, the density of compacted articles of this character such as memory cores must also be held accurate, thereby making it necessary that the amount of powder placed in each die cavity of the press must be substantially the same and must be repetitively maintained within extremely close limits. The finished density of all the finished cores must be the same; that is, it must be uniform and accordingly, the compression of the powdered material must be exact and repeatedly constant. If these dimensional and density specifications are not held within close tolerances the play back level from the cores in a memory bank will not be substantially constant from core to core. In order to realize acceptable dimensional tolerances, it is necessary that the press be capable of accurate adjustment of the movements of several component parts within at least 15 millionths of an inch, and that precautions be taken to insure correct fill of each die cavity.

In the preferred embodiment of the power compacting press as disclosed in the aforementioned US. patent and copending application, the articles are compacted and formed in a multi-cavity die forming part of the tool set. The finished articles are automatically ejected from the die, picked up by a vacuum suction head and swept out through discharge ports into suitable containers. A flipper assembly, which is part of the press, is mounted transversely movable over the die plate and carries a secondary powder hopper, an anvil, and a vacuum pick-up head. The secondary powder hopper which is supplied with powder from a primary hopper connected thereto by means of a flexible tubing or the like,

is first positioned over the die cavity or cavities, which are filled with powder to overflow, the punches are displaced upwardly so as to expel from the die cavities a predetermined amount of excess powder, the hopper is removed by a swinging movement of the flipper assembly, wiping the die plate surface clean. The anvil is in turn positioned on the upper surface of the die and over the die cavities.

The powder in each die cavity is then compacted against the anvil by way of pressure on the punches. The anvil is then removed from its position over the cavity or cavities and replaced by the vacuum pick-up head. The punches are then displaced so as to bring their upper ends substantially flush with the surface of each die through the die cavities, so that the finished compacted articles are ejected from the die cavities and picked up by the vacuum pick-up head. The vacuum pick-up head is then moved from over the die cavities and disposed over one or a series of discharge apertures arranged in a disposition similar to the arrangement of the die cavities in the die, and the finished articles are dropped through the discharge aperture or apertures into separate containers.

-In the aforementioned US. patent and copending patent application, the tool capsule or tool set for forming an article having a toroidal or circular shape comprises a die plate having one or a plurality of equiangularly spaced apertures which conveniently may be arranged in a circle, a punch associated with each of the apertures and adapted to be displaced in the aperture to form a confined die cavity for the powder between the head of the punch and the surface of the die plate, and a core rod for centrally apertured articles associated with each of the punches and axially adjustable within a longitudinal bore in the punch. In the prior art, during the compacting cycle, the core rod would be displaced upwardly in the cavity so that its head would be flush with the surface of the die plate and then the powder disposed around the core rod would be compressed by the punch moving toward the anvil immovably disposed over the cavity. Thus the movements of both the core rods and the punch had to be precisely controlled during each cycle.

The present invention represents an improvement over the aforementioned apparatus in that each of the core rods is adjusted to be flush with the upper surface of the die plate prior to placing the tool set in the machine and then it is held stationary in this position during the operation of the machine, while the punches are displaced axially in the cavities in a regular cycle to form compacted toroidal or circular shaped articles. Thus, the instantaneous position of only one movable member in the die cavity needs to be controlled, insuring a more accurate dimensional control.

A major problem associated with high production automatic powder compacting presses of this character is the maintenance of a high degree of surface finish of the various members exposed to the powder and associated with the dimensional tolerance of the finished articles. To insure a high degree of acceptable dimensional tolerances, the die plate and the punches are normally formed of a hardened tool steel or tungsten carbide and the surface of the die plate and the anvil are normally provided with a high degree of surface finish. However, some powdered substances, for instance powdered ferrite, used in the formation of computer memory cores have highly abrasive properties. Thus, the upper surface of the die plate tends to become pitted as the flipper assembly which traverses the die plate sweeps the excess powdered ferrite from the surface of the die plate prior to moving the anvil into engagement over the filled cavities. This sweeping action tends to wear the die plate so that acceptable dimensional tolerances are lost. In addition, the upper ends of the punches become worn due to their repeated compaction of the powdered ferrite. Normally, the conventional tool capsule has to be disassembled and the working surface of the die plate refinished, and the core rods refinished or replaced depending upon the amount of wear which has developed, and. then the various components reassembled for further utilization.

SUMMARY OF THE INVENTION The tool set illustrating the preferred embodiment of the present invention reduces the time and effort involved in renovating the working surfaces of the die plate and the core rods by providing a structure in which the die plate, core rods, punches, punch holder and related parts are removed as one complete assembly from the press, and all the parts can be refinished simultaneously by turning the assembly face down on a conventional lapping disk. The configuration of the several components is such that all of the working surfaces abut the lapping disk and are simultaneously finished or lapped.

It is, therefore, an object of the present invention to provide a tool set for a powder compacting press constructed to insure more reliable and repetitive control of dimensional tolerance by reducing to a minimum the number of moving parts associated with the finished member or article during each cycle.

It is another object of the present invention to reduce the time and effort in renovating the working surfaces of the tool set in a powder compacting press by providing such a tool set in which all of the working surfaces may be refinished without disassembling the tool set.

Still further objects and advantage of the present invention will become apparent to one skilled in the art upon reference to the following detailed description and the accompanying drawings in which like reference numerals represent like parts throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view partly in cross section of an exemplary powder compressing press embodying the present invention;

FIG. 2 is a schematic perspective view of the work area of the press of FIG. 1;

FIG. 3 to FIG. 5 schematically illustrate the working cycles of the press of FIG. 1;

FIG. 3a illustrates a modified preferred embodiment of a positioner and die plate assembly shown in the article eject and pick-up position;

FIGS. 6 to 11 are perspective views of various tool sets having single to multiple cavities and embodying the present invention;

FIG. 12 is a top plan view of a six cavity tool set;

FIG. 13 is a cross section through the tool set of FIG. 12 along line 1313;

FIG. 14 is a cross section through another embodiment of a multiple cavity tool set;

FIG. 15 is a partial plan view of the die plate of the tool set of FIG. 14, as seen along line 15--15;

FIG. 16 is a cross section through a further embodiment showing a single cavity tool set;

FIG. 17 is a side elevational view of the punch actuating assembly contained within the tool capsule of the tool set of FIG. 16;

FIG. 18 is a plan view of the die plate of the tool set of FIG. 16;

FIG. 19 is a transverse cross section through the tool capsule of :FIG. 16 along line 1919;

FIG. 20 is a bottom view of the tool capsule of FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Although the powder compacting press utilizing the tool capsules or tool set assemblies of the present invention forms no part of the invention herein disclosed, a brief summary of the construction and operation of an exemplary press is given hereafter for the sake of clarity.

With reference to FIGS. 1 and 2, the exemplary powder compacting press 22 has a base 24 supporting a frame 26 on which rests a work table 28. The frame encloses a drive mechanism 30 which comprises a camshaft 33 supporting a plurality of cams only two of which are shown at 32 and 35. Cam 32 is disposed so as to engage a cam r follower 31 mounted on the end of a treadle 34. The

treadle 34 which is centrally pivoted in the frame 26 on a shaft 37 is biased at one end towards the cam 32 by means of spring 25 and has at its other end, bifurcated as shown at 27 in FIG. 2 for driving through a spool member 29 a ram member 36 threaded on the internal bore of the spool member and supported below the work table 28 within a bushing 39 in the frame 26.

The ram 36 reciprocates the punch or punches of a tool set 40 by means of a punch actuating rod 41 mounted on the end of the ram 36. The tool set 40, which may be of any of the constructions shown in FIGS. 6 to 11, is mounted within an aperture 38 in the front end of the work table 28 and is suitably secured thereto by means of bolts 44 fitting into appropriate apertures provided in the die plate 42 of the tool set 40. The die plate 42 is flush with the surface of the work table 28 and is provided with one or several die cavities 43 and a corresponding number of discharge ports 45.

Positioned on top of the table 28 for pivotal sweeping movement around an arbor 51 driven in timed sequence by the motor of the press (not shown) is a station positioner or flipper assembly 46 provided with three work stations as follows:

(a) A fill station to dispense powdered material through a dispenser head 48 fed from a material hopper 50 by means of a flexible tube or conduit 49;

(b) A press station provided with an anvil 52 adapted to be clamped down upon the die plate 42 by means of a pivotal clamp 54; and

(c) An ejection station provided with a vacuum pickup head 56 which is connected to a source of vacuum (not shown) by means of a conduit 58 to suspend the finished article above the die cavity when ejected therefrom as will be explained.

With reference to FIGS. 1 to 5, synchronized and timed operation of the exemplary powder compacting press 22 is schematically as follows: After the machine is started, rotation of the camshaft 33 causes one of the cams of the multiple cam assembly-acting on suitable transmission means (not shown)to swing the positioner 46 to a position placing the dispenser head 48 over the die cavity or cavities 43, as shown in FIG. 3, to fill each of the cavities with powdered material 60 to an extent determined by the position of each punch 62 of the tool assembly 40 Within each die cavity 43. Hereafter the positioner 46 is caused to swing around in timed relation to position the press station or anvil 52 over the die cavity or cavities 43 (FIG. 4), the excess powder material remaining within the dispenser head 48. In timed sequence the anvil clamp 54 is actuated through the pivoting action of a lever 55 whose lower end is in abutment with cam 35 rotated by camshaft 33, as seen in FIGS. 1 and 2, to pivot around the clamp pivot 59 to press the anvil 52 down upon the die plate 42 over the cavities 43 (FIG. 4). Simultaneously, the punch 62 or each punch within the die cavity or cavities 43, is advanced upwardly as actuated by the cam force acting on the ram treadle 34 to compress the loosely dispensed powder 60 as shown. Thereafter, the positioner 46 is swung in timed sequence to a position placing the vacuum suction head 56 over the die cavity or cavities 43 '(FIG. to pick up the compressed article 64 from each of the die cavities 43 when ejected from the cavities by a further forced advance of the punch or punches 62 through the cavities to push the article 64 out of the cavities as shown, the articles being held against a protective screen 57 within the vacuum suction head 56. Thereafter, the positioner 46 is caused to rotate to its initial dispensing position of FIG. 3 which simultaneously place the finished articles 64 over the appropriately disposed discharge ports 45 to be released therethrough to fall into suitable separate containers (not shown).

As illustrated in FIG. 30, an alternate configuration provides for a modified positioner 46a supporting an anvil 52a, a dispenser head 48a and a pick-up head 56a in permitted locations relatively to the arrangement hereinbefore described. In the embodiment of FIG. 3a the anvil 52a is shown positioned between the dispenser head 48a disposed on the left thereof, as seen in the drawing, and the pick-up head 56a disposed on the right of the anvil. This arrangement has been found to be more practical and more in consistence with the work cycle of the press as will become evident.

The modified die plate 42a, in the example of FIG. 3a, has its discharge port or ports 45 located in accordance with the altered arrangement of the positioner. This is accomplished by the provision of a relatively large aperture 160 in the die plate near a corner thereof whose center lies on the arc extended from the center of the die cavities having a radius determined by the pivot axis of the positioner 46. The aperture 160 is adapted to receive an insert 162 provided with one or more discharge ports 45. The number of the discharge ports 45 in the insert 162 corresponds to the number of die cavities 43. When the positioner 46a is rotated from the eject and pickup position shown in FIG. 3a to a position placing the dispenser head 48a over the die cavities the pick-up head 56a is positioned over the discharge ports 45. At the same time the die cavities are again being filled with powdered material for the next work cycle.

As previously mentioned and as illustrated in FIGS. 3-5, the die cavity or cavities 43 are defined by hardened bushings 66 press-fitted into appropriate apertures 67 in the die plate 42 in order to absorb the compression forces and to provide a suitable bearing surface for the punch or punches 62 extending therethrough. As can further be seen, the powder material is compressed within the upper portion of the die bushing 66 between the anvil 52 and the punch 62 eliminating the serious die bushing wear between its ends as encountered in conventional powder compacting presses employing opposite upper and lower punches due to the relative high compacting pressures up to 15,000 lbs. per square inch. However, in the present invention it will be necessary to have accurate opposed planar surfaces on the anvil, die plate, die bushing and punch to maintain the required high accuracy as close as ten thousandths of an inch which is a necessity in the manufacturing of such items as memory or pulse transformer cores and the present invention is specifically constructed to maintain this accuracy by periodic simple resharpening of the complete tool set without disassembling as will be described hereafter.

Certain articles made from compacted powder materials require the provision of a hole and in order to provide this hole a core rod 68 is provided which generally extends axially through the center of the punch 62. Extreme difficulties have been encountered to position the core rod in such advanced position within the die cavity during the powder compacting operation so as to be accurately flush with the working surface 70 of the die plate 42 to maintain squareness of all surfaces and thus accurate dimensional consistency. As seen in FIG. 4, the interfaces of the working members abutting each other during the compressing cycle must be entirely flush with each other so as to maintain the internal and external sides of the finished articles square with its top and bottom surfaces and the present invention provides novel means to accurately and securely position and maintain the core rod 68 in flush relation with the die plate surface 70 regardless of the movement of the surrounding punch 62.

Various examples of the present novel tool set 40 are illustrated in FIGS. 6-11 in which FIG. 6 shows a onecavity tool set 40a, FIG. 7 a two-cavity tool set 4%, FIG. 8 a four-cavity tool set 400, FIG. 9 a six-cavity tool set 40d, FIG. 10 an eight-cavity tool set 40e, and FIG. 11 a twelve-cavity tool set 40 which are the most commonly employed cavity arrangements. Other arrangements with different numbers of cavities may, of course, be provided.

All of these tool sets 40a to 40 have an aperture 160 in the die plate in one corner thereof angularly offset from the die cavity or cavities 43 for the reception of an insert 162 having a corresponding number of discharge ports 45.

With reference now to FIG. 12, and to FIG. 13, which shows a tool set in an upside down position for a reason to be explained, and in which there is illustrated in more detail a six-cavity tool set 40d comprising a die plate 42 of generally rectangular shape having die cavities 43 preferably grouped in a circle and an insert aperture 160d for the reception of an insert 162d provided with multiple discharge ports 45 corresponding in number to the die cavities 43 to keep the finished workpieces from each die cavity separate. The die plate 42 is attached by means of bolts 72 to the upper end flange 74 of a cylindrical tool capsule housing 76. The tool capsule housing 76, as shown in FIG. 13, has an axial bore 78 having an internal diameter larger than a diameter circumscribed around the circularly arranged die cavities 43. The bore 78 in the lower end 77 of the tool capsule housing 76 is provided with an aligned end bore 80 of considerably smaller diameter through which the punch actuating rod 41 extends. The punch actuating rod 41 is provided with an enlarged head portion 82 which is slidable within the bore 78. The head portion 82 is provided with a number of radial slots or recesses 83 corresponding in number to the number of die cavities 43 in the die plate 42. The recesses or slots 83 are adapted to receive the punches 62 which also have a head portion 84 positioned at the bottom of the slots or recesses in order to be retained within the slots or recesses by means of lock rings 86. This arrangement provides individual self-alignment of the punches 62 within the die bushings 66 by the ability to slide within the slots 83 upon assembly of the tool set. The shanks 88 of the punches 62 extend through the die bushings 66 of which there is one provided for each die cavity 43. The punches 62 are axially bored through to each receive a core rod 68 of substantial length to extend through provided apertures 90 in the head portion 82 of the punch actuating rod 41 coaxial with the recesses 83 and to further extend into and through coaxial bores 92 in the lower portion 77 f the tool capsule housing 76 spaced around the reduced diameter bore 80 for the punch actuating rod 41. The lower ends 94 of the core rod 68 are thickened so as to provide a substantially tight fit Within the bores 92 and transverse set screws 96 are provided for each core rod through the lower portion 77 of the tool capsule housing to securely lock the core rods in their correct, adjusted position. Thus, it will be seen that with the core rods 68 locked in place, the punch actuating rod 41 is able to displace the punches 62 within the die bushings 66 by means of their securement to the punch rod head 82 by lock rings 86. The punch rod head 82 upon actuation by the machine ram 36 freely reciprocates within the enlarged bore 78 without disturbing the position of the core rods 68.

In order to correctly assemble the tool set d, so that all external surfaces of the die plate 42, die bushings 66, punches 62 and core rods 68 will be initially flush with each other, the die plate 42 is placed upside down upon an accurately machined flat plate 98 as illustrated in FIG. 13. The die bushings 66 have already been preassembled within their respective apertures provided in the die plate 42. Thereafter the preassembled tool capsule housing 76, likewise in upside down position, is put in place by letting the punches 62 extend into the respective die bushings 66. The capsule housing 76 is then secured to the underside of the die plate 42 by means of tightening bolts 72 extending through flange 74 into the die plate. Thereafter, the core rods 68 are pushed down upon plate 98 until they are exactly flush with the outer surface of the die bushings and the die plate surface and then are locked in this position by means of tightening set screws 96. The tool set 40d is then ready to be placed into the press 22 for the powder compacting operation.

The embodiment in FIGS. 14 and 15 illustrates a fourcavity tool set 400 which likewise comprises a die plate 42' having four cavities 43' grouped in a square substantially in the center thereof. A tool capsule housing 76 is attached by means of a flange 74' to the under-side of the die plate 42 and is provided with a number of longitudinal bores 100 corresponding in number to the number of die cavities. Each of the bores 100 slidably receives a cylindrical plug 102 axially adjustable therein and provided each with a central aperture 104 to allow the extension of punch rods 106 therethrough. Punch rods 106 are slidably disposed within the cylindrical plugs 102 and carry each a head portion or punch 108 which slidably extend into the die bushings 66 provided in each of the cavities 43'. The head portions or punches 108 of the punch rods 106 are each apertured as at 111 at equally spaced intervals to provide bores for a number of core rods 68 (in this instance four for each core rod head) slidably extending therethrough.

This tool set is adaptable to make circular, tablet-like articles having each four equally spaced holes. In order to correctly adjust the core rods 68' such that their tips will be flush with the surface of the die plate 42, the ends of the core rods are secured within the adjustable plugs 102 so that upon individual axial adjustment of the plugs 102 within the capsule bores 100 the core rods will be adjusted accordingly to be flush with the die plate surface 70' as shown, whereafter the plugs 102 are locked in the adjusted position by means of set screws extending through the lower end of the tool capsule housing, thus locking the core rods in accurate position relative to the die plate surface 70. Accurate simultaneous movement of the punch rods 106 to advance the punches 108 through the die bushings 66' is accomplished by the provision of a common punch rod holder 112 receiving and supporting all four of the punch rods 106 in their accurate spaced relation. Each of the punch rods 106 is individually secured within the punch rod holder 112 by means of set screws 114 engaging wedge shaped recesses 116 in the ends of the punch rods to enable individual axial adjustment and parallel vertical alignment of the punches within the die bushings 66' in relation to each other and to the die plate surface 70. The punch rod holder 112 is adapted to be engaged by the punch actuating rod 41 which is connected to the ram 36 of the machine so that upon reciprocation of the ram 36 the punch rods 106 will slide through the locked core rod plugs 102 so that the punches 108 will be reciprocated simultaneously within the die bushings 66 without affecting the position of the core rods 68.

The embodiment in FIGS. 16-20 discloses a one-cavity die set 400 comprising a die plate 42" having a central die cavity 43 and a discharge port 45 remote therefrom, the latter being provided within an insert 162a positioned in aperture 160a. A universal tool capsule housing 76" is attached to the underside of the die plate 42" by means of screws 72" within a flange 74". The tool capsule housing 76" has an axial bore 118 in the lower end of which is positioned an axially adjustable sleeve 120 which slidingly receives a punch holder 122 adapted to be engaged by the punch actuating rod 41 attached to the ram 36 of the machine. The upper end of the punch holder 122 within the bore 118 is provided with a transverse slot 124 (FIG. 19) having an undercut portion 126 to receive the flanged end 128 of a punch 130 to be securely locked thereto. Slidably disposed within an axial through bore 132 in the punch 130 is a core rod 134 which extends further into a blind bore 136 of the punch holder 122. The lower end of the core rod 134 within the punch holder 122 is provided with a transverse pin 138 having outwardly extended portions 140 adapted to extend through opposite longitudinal slots 142 and 144 provided in the punch holder 122 and into the adjustable sleeve 120 to be secured therein. Thus, the core 134 secured to the 1 adjustable sleeve 120 by means of the pin 138 for axial movement relative to the punch holder 122 and vice versa by means of the pin extending through the slots 142 and 144. Adjustment of the core rod 134 in order to be flush with the die plate surface 70" is accomplished by the provision of an external flange 146 on the sleeve 120 overlying the bottom surface 148 of the capsule housing 76". As seen in FIG. 20, the sleeve flange 14-6 is provided with a number of screws 150 for securement of the sleeve flange 146 to the capsule housing 76" and an equal number of set screws 152 equiangularly spaced which are adapted to abut the bottom surface 148 of the capsule housing 76" to thus space the sleeve flange 146 in adjusted position relative to the bottom surface 148 of the capsule housing.

In order to axially adjust the sleeve 120 and thus the core rod 134, the set screws 152 are loosened, whereafter, by means of screwing the screws 150 in or out, the sleeve 120 will be moved into or out of the capsule bore 118 in order to adjust the core rod 134 flush with the die plate surface 70". After correct adjustment, the set screws 152 are tightened against the bottom surface 148 of the capsule housing to securely lock the core rod 134 in place. It will be seen that, when ram force is provided by the ram 36 against the punch holder 122, the punch 130 is reciprocated within the die bushing 66 in the die cavity 43", the punch holder 122 moving freely within the sleeve 120 without disturbing the position of the core rod 134 due to the provision of the slots 142 and 144 through which the core rod pin 138 extends.

In all three of the embodiments described herein the tool sets are assembled and adjusted in the manner previously described by placing the assembly upside down upon an accurately machined planar surface to advance the core rods until they abut against the planar surface making them accurately flush with the die plate surface 70 and then securely locking the core rods in that position. The same procedure will be followed in maintenance of the tool when it becomes necessary to resharpen the die surfaces. The complete tool set is placed upside down upon a lapping surface for manual lapping of the worn edges.

CONCLUSION Because of the highly abrasive properties of some of the powdered substances utilized in presses of this character, the upper surface 70 of the die plate 42 and the upper ends of the core rods 60 and die bushings 66 tend to become fitted and worn and the edges become rounded off. The worn edges of the present novel tool set can be renovated by removing the tool set from the compacting press and inverting it so that the die plate 42 abuts upon a conventional lapping tool. By disengaging the respective set screws, the core rods 68 and the punches 62 are free to be moved upon the lapping tool so that all of the worn surfaces are simultaneously ground to the desired finish. Thus, it can be seen that the improved tool set can be renovated without disassembly of the various parts. Furthermore, it can be seen that a more precise dimensional control of the finished articles can be maintained in the improved tool set because of the fewer number of moving parts whose relative movements have to be accurately adjusted and controlled.

It can also be seen that the construction of the tool sets of the present invention provides for assembling the core rods and the punches in such manner that the core rods are individually precisely positioned longitudinally relative to the die plate 42 without the use of auxiliary members such as sleeves or the like to align and contain the core rods. The punch or punches are actuated in unison by means of a common actuating member, and the punches and core rods, although accurately located along a longitudinal axis, are substantially free to float such as to permit the punches and core rods to align themselves within the die bushings.

Although there has been described only a few preferred embodiments of the invention, it will be apparent to anyone skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention as expressed in the scope of the appended claims.

We claim:

1. A tool set for a powder compacting press comprising a die plate, a cylindrical tool capsule attached to one side of said die plate, at least one punch rod located within said cylindrical tool capsule for reciprocatory movement therein, a punch attached to the end of said punch rod, at least one aperture in said die plate registering with the interior of said cylindrical tool capsule, a bushing in said aperture adapted to receive said punch, said punch and said bushing defining a die cavity, at least one longitudinally adjustable core rod extending through said punch within said cylindrical tool capsule, said core rod being normally freely slidable within said punch and said cylindrical capsule but capable of being locked in a position such as to be flush with the surface of said die plate by means associated with said tool capsule separate from said core rod, said means comprising a sleeve member slidable within said cylindrical capsule, means to secure said core rod to said sleeve member, said sleeve member having flange means external of said cylindrical capsule adjacent the bottom end thereof, means to axially move said sleeve member into or out of said cylindrical capsule and adjustable abutment means associated with said flange means to adjustably limit longitudinal movement of said sleeve member.

2. In the tool, set defined in claim 1, said punch rod freely extending through said sleeve member and said means to secure said core rod to said sleeve member comprising a pin extending through slots within said punch rod and secured to said sleeve member to allow free reciprocating movement of said punch rod relative to said core rod and said sleeve member.

3. A multiple cavity tool set for a power compacting press comprising a cylindrical capsule having radially spaced axial through bores from end to end, a die plate attached to said capsule at one end thereof having apertures aligned with and corresponding in number to said axial through bores, bushings in said apertures of said die plate, plugs slidably inserted within the other ends of said axial through bores opposite said die plate, a punch rod slidably extending through each of said plugs having a punch at its upper end extending within each of said bushings, core rods attached to each of said plugs and slidably disposed within each of said punches in parallel alignment to each other, said plugs being individually movable in or out of said through bores for adjusting the position of said core rods in relation to each of said punches with which said core rods are associated, and individual means to lock said plugs in adjusted position to prevent axial movement of said core rods relative to said punches.

4. The multiple cavity tool set as defined in claim 3, further comprising holding means separate from said cylindrical capsule for connecting the ends of said punch rods to a punch actuating means and means to individually adjust and lock said punch rods to said holding means in axially aligned position relative to said bushings in said die plate.

5. In the multiple cavity tool set defined in claim 4, said individual adjusting and locking means comprising wedge shaped notches in said punch rods adapted to be engaged by set screws within said holding means.

6. In the multiple cavity tool set defined in claim 3, said means to lock said plugs comprising set screws located within said capsule;

7. A unitary tool and die assembly for use in a powder compacting press comprising a die plate having a work surface and a bottom surface, a tool capsule attached to said bottom surface of said die plate, said die plate having an aperture adapted to secure a die bushing and centered in relation to the central axis of said tool capsule, a sub-assembly comprising a punch rod having a cylindrical punch attached thereto, a core rod extending through said punch and into said punch rod, a flanged cylindrical sleeve surrounding said punch rod, means to connect said core to said sleeve comprising a pin extending through said punch rod into said sleeve, said core rod and said sleeve being axially movable relative to said punch rod and said punch, said sub-assembly adapted to References Cited UNITED STATES PATENTS 2,127,994 8/1938 Davis et al. 18l6.5X 2,338,491 1/1944 Cutler -1 1816.5 2,3 62,048 11/1944 Cherry et a1.

2,867,844 1/1959 Hall 1816.5 3,168,759 2/1965 Johannigman 1816.7 3,328,840 7/1967 Vinson 18-16A 3,382,540 5/1968 Van De Maden et a1. 1816.5 3,414,940 12/1968 Vinson 18--16H J. HOWARD FLINT, JR., Primary Examiner 

